Stealth Omicron: The 18 areas of England with highest rates of highly contagious coronavirus variant

The contagious ‘Stealth Omicron’ strain of coronavirus has already become dominant in parts of England, new analysis shows.

The Omicron sub-variant, officially called BA.2, now accounts for a quarter of cases in England, up from one in 100 a month ago, according to research by the Wellcome Sanger Institute.

Stealth Omicron was named a ‘variant under investigation’ on January 21 and is now on track to become the dominant strain in the UK.

It got its nickname because it is more difficult to differentiate from Delta than the original Omicron variant, BA.1.

It also appears to be more contagious.

But there is not yet enough data to show whether BA.2 causes more severe disease than the original Omicron variant, the UK Health Security Agency has said.

The Wellcome Sanger Institute analysed 38,000 positive Covid-19 tests taken in the week to February 12 to determine which variant they were.

Its research did not include Scotland, Northern Ireland or Wales.

Areas with fewer than 10 samples have been omitted.

Here are the 18 areas which had the highest percentage of the strain, according to the data.